1. Field of the Invention
Rotor blades for wind power installations are known in many different forms. In a wind power installation the rotors or the rotor blades thereof represent the main source of sound. For reasons relating to acceptance and noise prevention laws, the aim should/must be that of minimizing the levels of sound emission as wind power installations are often also set up in the proximity of residential accommodation. The levels of sound emission which hitherto occur with a wind power installation or a wind power converter also mean that wind power installations are faced with resistance from populated areas because of the sound they produce and for that reason such installations can be accepted sometimes with difficulty or not at all as authorities responsible for planning permission refuse permission for wind power installations because of the existing environmental requirements, noise also being an environmentally polluting factor.
2. Description of the Related Art
Many proposals have already been put forward for structurally modifying a rotor blade of a wind power installation in such a way as to afford a reduction in noise. By way of example reference is made here to the documentation as is disclosed in EP-A-0 652 367 or DE 196 14 420.5.
However a reduction in noise by virtue of structural measures on the rotor blade is possible only to a limited extent.